The present invention relates to harvesting machinery drive systems, and more particularly to hydraulic drive systems for machines which separate crops from vines by shaking action.
In the large-scale harvesting of tomatoes, it has been a common practice for many years to employ machinery wherein a mass of vines and tomatoes is fed to an oscillating shaker conveyor which shakes the crop loose and allows it to pass through the shaker chain to be recovered as the vines are discarded back into the field. Early patents disclosing vertical oscillation of travelling shaker chains include U.S. Pat. Nos. 1,107,765 of Klinghammer, 2,711,742 of Lavern and 3,106,249 of Zachery. Improvements in the shaker mechanism and drive as specifically applied to the harvesting of tomatoes are disclosed in numerous other patents such as U.S. Pat. Nos. 3,071,196 of Scheidenhelm, 3,301,331 of Looker, et al, and 3,633,677 of Walker.
U.S. Pat. No. 3,810,512 relates to further improvements in such harvesting apparatus employing a plurality of rotating arms along each side of the shaker belt. The arms carry rollers on each end for contacting the lower side of the upper run of the chain. Alternate arms along each side are arranged at 90.degree. to one another; that is, when the rotational position of each arm is prependicular to the direction of chain travel and thus lifting the chain to the maximum extent, the adjacent arms (or arm, in the case of the endmost arms) are positioned parallel to the direction of chain travel. This rotational relationship is maintained by providing a sprocket on each arm, connection all sprockets along each side by drive chains and imparting rotation from a master sprocket driven by a single hydraulic motor.
It is a principal object of the present invention to provide a drive system for the oscillating machanism of a tomato harvester shaker chain which improves the operating efficiency of the harvester.
Another object is to provide a tomato harvester wherein the speed of various groups of driving mechanism may be individually and selectively controlled to achieve improved operating efficiency.
A further object is to provide a hydraulic drive system for a tomato harvester which enhances the ability of the shaker chain to remove the crop from the vine, thereby allowing faster operating speeds and harvesting a greater amount of crop in less time than is normally achieved with present harvesters.
Other objects will in part be obvious and will in part appear hereinafter.